The Treatment and Alteration of Gemstones
There are various methods and materials used to treat gemstones. A gem may be treated in many ways to enhance the beauty of an authentic gem.
Dyeing
Onyx
Black Onyx occuring in large quantities is rare. Therefore, it is is typically dyed to create a pure black stone. The dying treatment consists of agate which is stained using a sugar-sulphuric acid treatment, then soaked in a sugar solution, then heated in sulphuric acid to carbonize the sugar.
